Apparatus and methods for clot disruption and evacuation

ABSTRACT

The apparatus includes a catheter having a combined infusion/aspiration lumen, a three lumen proximal portion and a two lumen distal portion. An infusion/aspiration valve located at the distal end of the catheter facilitates performing infusion and aspiration through the same lumen, which in turn reduces the number of lumens, and enables the combined infusion/aspiration lumen to be made larger without the need to increase the diameter of the catheter. Differing material properties in the proximal and distal portions of the catheter enable the proximal portion to be made stiffer for pushability, while the distal portion is more flexible to navigate tortuous vasculature and enable a greater amplitude agitator to be received within the catheter.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of and claims the benefit of U.S.patent application Ser. No. 13/835,324 filed Mar. 15, 2013, now U.S.Pat. No. 9,332,998, which claims priority to provisional applicationSer. No. 61/682,478, filed on Aug. 13, 2012, the entire contents ofwhich are hereby incorporated by reference.

TECHNICAL FIELD

The present embodiments relate to apparatus and methods for disruptingand evacuating occlusive material from blood vessels.

BACKGROUND

Thrombosis and atherosclerosis are ailments that result from depositionof thrombus or atheromas, respectively, in the luminal walls of bloodvessels. When hardened, such deposits typically result in vascularobstruction and reduced blood flow through the lumens of affected bloodvessels. Thrombosis and atherosclerosis are most common in theperipheral blood vessels that feed the limbs of the human body, and thecoronary arteries, which feed the heart. Stasis, incompetent valves, andtrauma in the venous circulation cause thrombosis, particularlyoccurring as a deep vein thrombosis in the peripheral vasculature. Whensuch deposits accumulate in localized regions of the blood vessel, theycan restrict blood flow and cause a serious health risk.

In addition to forming in the natural vasculature, thrombosis is aserious problem in “artificial” blood vessels or autologous blood vesselgrafts, particularly in peripheral femoral-popliteal and coronary bypassgrafts and dialysis access grafts and fistulas. The creation of suchartificial blood vessels requires anastomotic attachment at at leastone, and usually at at least two, locations in the vasculature. Suchsites of an anastomotic attachment are particularly susceptible tothrombus formation due to narrowing caused by intimal hyperplasia, andthrombus formation at these sites is a frequent cause of failure of theimplanted graft or fistula. The arterio-venous grafts and fistulas thatare used for dialysis access are significantly compromised by thrombosisat the sites of anastomotic attachment and elsewhere. Thrombosis oftenoccurs to such an extent that the graft needs to be replaced within afew years or, in the worst cases, a few months.

A variety of methods have been developed for treating thrombosis andatherosclerosis in the coronary and peripheral vasculature, as well asin implanted grafts and fistulas. Such techniques include surgicalprocedures, such as coronary artery bypass grafting, mid minimallyinvasive procedures, such as angioplasty, atherectomy, thrombectomy,thrombolysis, transmyocardial revascularization, etc.

Some techniques for treating thrombosis and atherosclerosis includedissolving clots using thrombolytic agents. Examples of thrombolyticagents include tissue plasminogen activator (tPA), streptokinase,urokinase, etc. Such thrombolytic agents may be delivered systemicallyor locally. When delivered locally, the treatment may be coupled withmechanical disruption of the clot and evacuation from the vessel lumen.

SUMMARY

The various embodiments of the present apparatus and methods for clotdisruption and evacuation have several features, no single one of whichis solely responsible for their desirable attributes. Without limitingthe scope of the present embodiments as expressed by the claims thatfollow, their more prominent features now may be discussed briefly.After considering this discussion, and particularly after reading, thesection entitled “Detailed Description,” one will understand how thefeatures of the present embodiments provide the advantages describedherein.

Many of the present embodiments are described as including variouscombinations of features and/or components. It should be understood thatthese combinations are merely examples. Additional embodiments maycomprise combinations of features and/or components different from thosedescribed here. For example, certain features and/or components may beomitted from various embodiments and/or combined with features and/orcomponents shown in other combinations herein.

The present embodiments provide apparatus, methods, and kits fordisrupting and dissolving thrombus present in a patient's vasculature.The thrombus, also referred to as clot, may be present in both thearterial and venous vasculature, as well as the peripheral venousvasculature, and grafts. The present embodiments are particularly suitedfor treating thrombotic disease within the venous vasculature, such asthrombosis in the superficial veins, the central veins, thefemoral-popliteal veins, the iliofemoral vein, etc. The presentembodiments are also particularly suited for treating arterialthrombotic disease, such as thrombosis in the iliofemoral artery, thesuperficial femoral artery, etc.

The present embodiments provide apparatus and methods for infusingthrombolytic agents, aspirating dissolved clot, and any solid clot thatmay be present, and passing a guide wire, all through a common catheterlumen. Other embodiments may provide for separate lumens for infusing,aspirating and/or passing a guide wire. Embodiments with fewer lumensmay provide the additional advantage of having a relatively smalldiameter compared to other devices.

In a first aspect, apparatus for disrupting clot over a luminal lengthof a blood vessel according to the present embodiments comprises acatheter body having a proximal end, a distal end and at least onelumen. At least one opening along a treatment length of the catheterbody allows infusion, of a thrombolytic agent and/or aspiration ofdissolved clot, and any solid clot that may be present. The catheterbody further includes at least one radially expandable body forinhibiting flow of clot beyond the luminal length of the blood vessel.

The dimensions and materials of the catheter body may be selectedaccording to characteristics of a treatment site within the vasculatureto be treated. For example, the catheter may be sized to be introducedpercutaneously or via a cut down to the vasculature at an entry, andthen be intravascularly advanced, typically over a guide wire, to thetreatment site. Treatment sites in the peripheral, coronary, andcerebral vasculature may generally be approached through differentaccess sites, and may require catheters having different lengths,diameters, and flexibilities.

The luminal length of the blood vessel to be treated may be at least 3cm, at least 10 cm, in the range from 3 cm to 100 cm, and usually from 5cm to 55 cm. The length of thrombotic disease being treated may varydepending on the location of the disease within the vasculature. Forexample, deep vein thrombosis is often spread over a length in the rangefrom 5 cm to 100 cm. The apparatus and methods of the presentembodiments are capable of treating disease spread over these lengths asdescribed in more detail below.

The apparatus of the present embodiments need not be adapted to treatthe entire length of the diseased region at once. It will often bepossible and in some cases desirable to treat discrete lengths withinthe entire diseased region separately. Such discrete lengths may betreated successively, e.g., by axially translating the treatment devicewithin the blood vessel being treated. Alternatively, the segments couldbe treated using different devices, optionally introduced from differentintroduction sites in the vasculature.

When the blood vessel is a vein, the target site may be selected fromthe vena cava, the iliac vein, the femoral vein, the popliteal vein, thecommon iliac vein, the external iliac vein, the brachial vein, thesubclavian vein, or any other vein. When the target blood vessel is anartery, the target site may be selected from the internal iliac artery,the external iliac artery, the popliteal artery, the coronary arteries,the superficial femoral artery, the brachial artery, or any otherartery.

In various embodiments, the at least one opening in the treatment lengthof the catheter may include one opening in a side wall of the lumen ofthe catheter body, multiple smaller spaced-apart openings in the lumen,a combination of multiple smaller openings and one larger opening, etc.Generally, the at least one opening may have any suitable configurationfor infusing an agent and/or aspirating dissolved clot, and any solidclot that may be present.

Some of the present embodiments further include a mechanical agitatoralong the treatment length of the catheter body for mechanicallyagitating clot at the treatment site and/or for dispersing lytic at thetreatment site. The mechanical agitator may have a wide variety ofspecific configurations. For example, the mechanical agitator maycomprise a radially expansible agitator that is rotatable and/or axiallytranslatable within the catheter body. In certain embodiments, theradially expansible agitator may be self-expanding. For example, it maycomprise a resilient element that may be radially constrained to have alow profile (small diameter) and may be freed from radial constraint tohave an enlarged profile (large diameter) with a non-linear geometry.Radial constraint may be provided by a sleeve or sheath that may beaxially advanced and retracted relative to the catheter body to coverand uncover the radially expansible agitator. In this way, the cathetermay be introduced to a treatment site within the vasculature with theexpansible agitator covered (and thus radially constrained). After thedesired treatment site is reached, the sheath or sleeve may be axiallyretracted to release the radially expansible agitator so that it expandsto engage the clot in the blood vessel. The agitator may then be rotatedand/or axially translated to engage and disrupt the clot in combinationwith the release of a thrombolytic agent, as described in more detailbelow. Such rotation, oscillation, and/or translation may be performedusing a motor drive unit operatively connected to the agitator, or maybe performed manually in whole or in part.

In an alternative embodiment, the radially expansible agitator maycomprise a resilient element that may be axially shortened to assume anenlarged profile having a non-linear geometry. For example, aself-expanding resilient element may be straightened (tensioned) byinitially positioning a rod or stylet therein in order to lengthen theelement and cause it to straighten to a low profile diameter. Theagitator may then be expanded by retracting the rod or stylet to releasethe agitator from tension and permit the agitator to radially expand asa result of the agitator's inherent spring force. Alternatively, theagitator may be formed to have a generally straight, low profileconfiguration and be actively caused to radially expand by pulling on arod or wire to cause axial shortening.

The agitator may have a variety of specific geometries, such as ahelical geometry, a spiral geometry, a serpentine geometry, a zig-zaggeometry, an alternating helix geometry (e.g., two or more helicalgeometries in tandem where successive helixes are wound in oppositedirections), and/or a variety of other random geometries. The geometriesmay be such that the resilient element can engage against and penetrateinto the clot within a blood vessel as the resilient element is radiallyexpanded. As the resilient element is thereafter rotated and/or axiallytranslated, the element then mechanically engages and disrupts the clot.By simultaneously introducing the thrombolytic agent directly to theregion that is being mechanically engaged by the agitator, disruptionand dissolution of the clot is significantly enhanced.

In the present embodiments that include a mechanical agitator, theapparatus may be configured to release the thrombolytic agent alongsubstantially the entire length of the agitator that is in contact withthe clot to be disrupted. In this way, the thrombolytic agent may bereleased at the point of mechanical agitation, resulting in bothimproved distribution of the thrombolytic agent into the clot as well asimproved disruption and dissolution of the clot.

In certain embodiments, the agitator may be configured as a tube havinga thrombolytic agent delivery lumen therein. The tube may have agentdelivery ports and/or porous regions to permit the release of thethrombolytic agent at the treatment site. In this way, the thrombolyticagent may be delivered while the agitator is deployed within thecatheter.

The clot disruption and dissolution apparatus of the present embodimentsmay further comprise means for isolating at least one end of thetreatment site to reduce blood flow through the region being treated.For example, at least one balloon may be provided on the catheter bodydistally or proximally of the agitator and thrombolytic agentdistribution region. When only a single balloon is used for isolation,it is preferably downstream from the treatment site. This arrangementinhibits the loss of the thrombolytic agent as well as the release ofemboli downstream. Preferably, isolation means are provided on both thedistal and proximal sides of the agitator and thrombolytic agentdistribution region. The isolation means may comprise a pair of axiallyspaced-apart balloons disposed on the catheter body. Optionally, one ofthe balloons is disposed on a separate, telescoping portion of thecatheter body in order to permit length adjustment of the region to beisolated. Alternatively, a variety of other isolation means, such asdeployable flanges, malecot structures, expansible braids, etc, couldalso be employed.

In another apparatus aspect, the present embodiments provide anapparatus for disrupting clot over a target region of a blood vessel.The apparatus comprises a catheter body having a proximal end and adistal end. An agitator is disposed near the distal end for mechanicallyagitating clot over the target region. A port near the distal end is influid communication with an agent supply source for distributing anagent along the target region.

In many embodiments, the agent will comprise a thrombolytic agent, whichmay provide an enzymatic action to break down fibrin clot matrix. Avariety of other agents may also be used, including group IIb/IIIaInhibitors (to inhibit fibrinogen binding site of platelet membrane),other anti-platelet agents, anti-thrombin agents and agents directedtoward prevention of restenosis (which may inhibit coagulation and/orinhibit restenosis by decreasing smooth muscle proliferation andmigration), gene therapeutic agents (for preventing restenosis andpromoting angiogenesis), chemotherapeutic agents (generally designed totreat malignancies), imaging media, and/or other potential agents.

The methods of the present embodiments allow for a wide variety ofparticular treatment protocols. For example, the agitator may be drivenat different and/or variable speeds. The agitator may be rotated and/oroscillated at speeds in the range from 0 rpm to 50,000 rpm, preferablyfrom 50 rpm to 5,000 rpm. The speeds may be set and/or adjusted at awide variety of particular rotational speeds within these ranges. Insome cases, the direction of the rotation may be reversed during thecourse of the procedure. The agitator may further be axially advanced orretracted during the course of treatment to enhance the disruption ofthe clot and introduction of the thrombolytic into the clot.

The treatment methods of the present embodiments may further compriseaspiration of the disrupted clot from the treatment site. Aspiration maybe accomplished using a lumen or lumens within the sheath and/oragitator to withdraw the disrupted clot. Optionally, mechanical means,such as an Archimedes screw or other pump, may be incorporated into thecatheter to enhance the aspiration and removal of the disrupted clot. Inother embodiments, such a pump may be mounted to a separate structure,such as to a sheath removably disposed over the catheter, an innerstructure removably disposed within a lumen of the catheter, etc. Stillfurther embodiments may rely on an aspiration means that remains outsidethe patient, such as a syringe, vacuum container, etc.

In some embodiments, blood may be periodically or continuouslyintroduced into the treatment region. tPA acts on plasminogen within thevasculature to breakup thrombus. If the treatment region of the presentembodiments are isolated, it may be beneficial to introduce fresh bloodcontaining plasma in order to enhance the activity of the thrombolyticagent, particularly tPA. Most simply, fresh blood could be introduced byperiodically opening an isolation balloon that isolates the treatmentregion.

The methods of the present embodiments can rely on two or more of thetreatment catheters to be used simultaneously. For example, in thetreatment of arterio-venous grafts, it is possible to introduce twotreatment catheters according to the present embodiments, each of whichhas a balloon or other occlusion device at its distal end, to an A-Vgraft at a point near its middle. By introducing the two treatmentcatheters in opposite directions, the graft may be isolated very closeto the points at which it is anastomosed to the natural vasculature.After such isolation is achieved, the interior of the A-V graft can thenbe cleaned out according to the methods of the present embodiments, andpreferably the released clot and thrombus may be withdrawn through anaccess sheath to the A-V graft.

The present embodiments still further comprise kits, including acatheter having an agitator and a thrombolytic agent delivery means. Thekits further include instructions for use according to any of themethods set forth above and/or below. In addition to the catheter andthe instructions for use, the kits may further comprise packaging, sucha box, pouch, tray, tube, hag. etc. that holds the catheter and theinstructions for use. The catheter may be maintained sterile within thepackage, and the instructions for use may be printed on a separatepackage insert or piece of paper. Alternatively, the instructions foruse may be printed in whole or in part on a portion of the packaging.

One of the present embodiments comprises apparatus for disrupting a clotin a blood vessel, the apparatus comprising: a catheter body having aproximal length and a treatment length; at least one port along theproximal length of the catheter body; at least one infusion openingalong the treatment length of the catheter body; at least one aspirationopening along the treatment length of the catheter body; a first lumenwithin the catheter body in fluid communication with the infusionopening and in fluid communication with the aspiration opening; a valvemember along the treatment length of the catheter body, the valve beingconfigured to selectively open and close fluid communication between theport and the aspiration opening; and an agitator that is translatablelongitudinally within the first lumen. In a further aspect of thepresent embodiment, the valve member comprises a body that istranslatable longitudinally within the first lumen. In a further aspectof the present embodiment, the body comprises a first position locatedproximally of the aspiration opening and a second position locateddistally of the aspiration opening. In a further aspect of the presentembodiment, when the body is in the first position the apparatus isconfigured to infuse a thrombolytic agent into the vessel through thefirst lumen and the infusion opening, and when the body is in the secondposition the apparatus is configured to aspirate dissolved clot, and anysolid clot that may be present, from the vessel through the aspirationopening and the first lumen. A further aspect of the present embodimentcomprises an aspiration source; wherein when the body is in the firstposition the body substantially blocks fluid communication within thefirst lumen between the aspiration opening and the aspiration source,and when the body is in tire second position the body does not blockfluid communication within the first lumen between the aspirationopening and the aspiration source. A further aspect of the presentembodiment comprises an infusion source; wherein when the body is in thefirst position the body substantially blocks fluid communication withinthe first lumen between the aspiration opening and the infusion source,the body therefore being configured to cause fluid flowing from theinfusion source to flow out of the first lumen through the at least oneinfusion opening. In a further aspect of the present embodiment, theagitator comprises an elongate member having a non-linear portion alongthe treatment length of the catheter body. In a further aspect of thepresent embodiment, the body is located in a distal portion of theagitator and is translatable therewith along the first lumen. A furtheraspect of the present embodiment comprises a first expandable memberalong the treatment length of the catheter body, the first expandablemember defining a first expandable internal volume. A further aspect ofthe present embodiment comprises a second lumen within the catheter bodyin fluid communication with the first expandable internal volume of thefirst expandable member. A further aspect of the present embodimentcomprises a second expandable member along the treatment length of thecatheter body, the second expandable member defining a second expandableinternal volume. A further aspect of the present embodiment comprises athird lumen within the catheter body in fluid communication with thesecond expandable internal volume of the second expandable member. In afurther aspect of the present embodiment, the second lumen terminates atthe first expandable internal volume of the first expandable member andthe third lumen terminates at the second expandable internal volume ofthe second expandable member. In a further aspect of the presentembodiment, the infusion opening and the aspiration opening are locatedbetween the first and second expandable members. In a further aspect ofthe present embodiment, the at least one infusion opening comprises aplurality of infusion openings that are spaced radially around thecatheter body, over a radial span of greater than 180° about thelongitudinal axis of the catheter body. In a further aspect of thepresent embodiment, the infusion openings are located on a portion ofthe catheter body that comprises no lumens other than the first lumenand the second lumen, the first lumen and the second lumen beingcollectively sufficient to facilitate infusion through the infusionopenings, aspiration through the aspiration opening, and expansion ofone of the expandable members. In a further aspect of the presentembodiment, the catheter body comprises a proximal portion and a distalportion secured to one another at a joint, and the first expandablemember surrounds the joint. In a further aspect of the presentembodiment, the joint is a butt joint. In a further aspect of thepresent embodiment, the at least one infusion opening comprises aplurality of infusion openings, and the infusion openings are spacedfrom one another both radially and longitudinally with respect to thetreatment length of the catheter body. In a further aspect of thepresent embodiment, the infusion openings are grouped in groups ofthree, with each group of three infusion openings being located at asame position along the treatment length of the catheter body. In afurther aspect of the present embodiment, the infusion openings in eachgroup of three infusion openings are uniformly radially spaced 120° fromone another. In a further aspect of the present embodiment, the agitatoris configured to mechanically disrupt the clot and/or to disperse lyticto facilitate dissolving the clot.

Another of the present embodiments comprises apparatus for disrupting aclot in a blood vessel, the apparatus comprising: a catheter body havinga proximal length and a treatment length; at least one port along theproximal length of the catheter body; at least one infusion openingalong the treatment length of the catheter body; at least one aspirationopening along the treatment length of the catheter body; a first lumenwithin the catheter body in fluid communication with the infusionopening and in fluid communication with the aspiration opening; meansfor selectively opening and closing fluid communication between the portand the aspiration opening; and an agitator that is translatablelongitudinally within the first lumen. In a further aspect of thepresent embodiment, the means includes a body portion located within thefirst lumen. In a further aspect of the present embodiment, the bodyportion is translatable longitudinally between a first position locatedproximally of the aspiration opening and a second position locateddistally of the aspiration opening. In a further aspect of the presentembodiment, when the body portion is in the first position the apparatusis configured to infuse a thrombolytic agent into the vessel through thefirst lumen and the infusion opening, and when the body portion is inthe second position the apparatus is configured to aspirate dissolvedclot, and any solid clot that may be present, from the vessel throughthe aspiration opening and the first lumen. A further aspect of thepresent embodiment comprises an aspiration source; wherein when the bodyis in the first position the body substantially blocks fluidcommunication within the first lumen between the aspiration opening andthe aspiration source, and when the body is in the second position thebody does not block fluid communication within the first lumen betweenthe aspiration opening and the aspiration source. A further aspect ofthe present embodiment comprises an infusion source; wherein when thebody is in the first position the body substantially blocks fluidcommunication within the first lumen between the aspiration opening andthe infusion source, the body therefore being configured to cause fluidflowing from the infusion source to flow out of the first lumen throughthe at least one infusion opening. In a further aspect of the presentembodiment, the agitator comprises an elongate member having anon-linear portion along the treatment length of the catheter body. In afurther aspect of the present embodiment, the body portion is located ina distal portion of the agitator and is translatable therewith along thefirst lumen. In a further aspect of the present embodiment, the at leastone infusion opening comprises a plurality of infusion openings that arespaced radially around the catheter body, over a radial span of greaterthan 180° about the longitudinal axis of the catheter body. In a furtheraspect of the present embodiment, the infusion openings are located on aportion of the catheter body that comprises no lumens other than thefirst lumen and a second lumen, the first lumen and the second lumenbeing collectively sufficient to facilitate infusion through theinfusion openings, aspiration through the aspiration opening, andexpansion of one of the expandable members. In a further aspect of thepresent embodiment, the agitator is configured to mechanically disruptthe clot and/or to disperse lytic to facilitate dissolving the clot.

Another of the present embodiments comprises apparatus for disrupting aclot in a blood vessel, the apparatus comprising: a catheter body havinga proximal length and a treatment length; at least one port along theproximal length of the catheter body; at least a first opening along thetreatment length of the catheter body; a first lumen within the catheterbody in fluid communication with the opening; a body member axiallytranslatable within the first lumen between a first position locatedproximally of the opening and a second position located distally of theopening; and an agitator that is translatable longitudinally within thefirst lumen. In a further aspect of the present embodiment, when thebody member is in the first position fluid communication between theport and the opening is closed, and when the body member is in thesecond position fluid communication between the port and the opening isopen. In a further aspect of the present embodiment, the agitatorcomprises an elongate member having a non-linear portion along thetreatment length of the catheter body. In a further aspect of thepresent embodiment, the body member is located in a distal portion ofthe agitator and is translatable therewith along the first lumen. Afurther aspect of the present embodiment comprises at least a secondopening along the treatment length of the catheter body. In a furtheraspect of the present embodiment, the first opening is configured foraspiration of dissolved clot, and any solid clot that may be present,from within the vessel and the second opening is configured for infusionof a thrombolytic agent into the vessel. A further aspect of the presentembodiment comprises an aspiration source; wherein when the body is inthe first position the body substantially blocks fluid communicationwithin the first lumen between the aspiration opening and the aspirationsource, and when the body is in the second position the body does notblock fluid communication within the first lumen between the aspirationopening and the aspiration source, A further aspect of the presentembodiment comprises an infusion source; wherein when the body is in thefirst position the body substantially blocks fluid communication withinthe first lumen between the aspiration opening and the infusion source,the body therefore being configured to cause fluid flowing from theinfusion source to flow out of the first lumen through the at least oneinfusion opening. In a further aspect of the present embodiment, theagitator is configured to mechanically disrupt the clot and/or todisperse lytic to facilitate dissolving the clot.

Another of the present embodiments comprises a method for disrupting aclot at a treatment location in a blood vessel, the method comprising:positioning a treatment length of a catheter body at the treatmentlocation; positioning a valve body, also called an occluding body,within a first lumen of the catheter body proximally of an aspirationopening in a sidewall of the catheter body, the aspiration opening beinglocated along the treatment length of the catheter body; infusing athrombolytic agent into the vessel through the lumen and at least oneinfusion opening located along the treatment length of the catheterbody; activating an agitating mechanism located along the treatmentlength of the catheter body to disrupt the clot and to disperse lytic atthe treatment site; advancing the occluding body within the first lumenof the catheter body until it is positioned distally of the aspirationopening; and aspirating dissolved clot, and any solid clot that may bepresent, from the vessel through the aspiration opening and the firstlumen. In a further aspect of the present embodiment, the agitatingmechanism comprises an elongate member having a non-linear portion alongthe treatment length of the catheter body. In a further aspect of thepresent embodiment, activating the agitating mechanism comprisesrotating and/or axially translating the agitating mechanism within theblood vessel and against the clot. In a further aspect of the presentembodiment, the occluding body is located in a distal portion of theagitating mechanism, and advancing the occluding body within the firstlumen comprises advancing the agitating mechanism. In a further aspectof the present embodiment, wherein positioning the occluding bodyproximally of the aspiration opening further comprises directing fluidflow from an infusion source through the infusion opening and notthrough the aspiration opening. A further aspect of the presentembodiment comprises expanding a first expandable member located alongthe treatment length of the catheter body until the vessel is occludedby the first expandable member. A further aspect of the presentembodiment comprises expanding a second expandable member located alongthe treatment length of the catheter body until the vessel is occludedby the second expandable member, wherein the first and second expandablemembers are located on either side of the clot. In a further aspect ofthe present embodiment, expanding the first expandable member comprisesintroducing fluid into a first expandable internal volume of the firstexpandable member through a second lumen of the catheter body. In afurther aspect of the present embodiment, expanding the secondexpandable member comprises introducing fluid into a second expandableinternal volume of the second expandable member through a third lumen ofthe catheter body. In a further aspect of the present embodiment, thesecond lumen terminates at the first expandable internal volume of thefirst expandable member and the third lumen terminates at the secondexpandable internal volume of the second expandable member. In a furtheraspect of the present embodiment, the infusion opening and theaspiration opening are located between the first and second expandablemembers. In a further aspect of the present embodiment, the catheterbody comprises a proximal portion and a distal portion secured to oneanother at a joint, and the first expandable member surrounds the joint.In a further aspect of the present embodiment, the joint is a buttjoint. In a further aspect of the present embodiment, infusing thethrombolytic agent comprises forming a plurality of outflows of theinfused agent that are spaced radially around the catheter body, over aradial span of greater than 180° about the longitudinal axis of thecatheter body. In a further aspect of the present embodiment, theoutflows are formed along a portion of the catheter body that comprisesthe first lumen and a second lumen; further comprising achievinginfusion via the plurality of outflows, aspiration through theaspiration opening, and expansion of an expandable member, all by usingno catheter body lumens other than the first lumen and the second lumen.In a further aspect of the present embodiment, the at least one infusionopening comprises a plurality of infusion openings, and the infusionopenings are spaced from one another both radially and longitudinallywith respect to the treatment length of the catheter body. In a furtheraspect of the present embodiment, the infusion openings are grouped ingroups of three, with each group of three infusion openings beinglocated at a same position along the treatment length of the catheterbody. In a further aspect of the present embodiment, the infusionopenings in each group of three infusion openings are uniformly radiallyspaced 120° from one another.

Another of the present embodiments comprises a method for disrupting aclot at a treatment location in a blood vessel, the method comprising:positioning a treatment length of a catheter body at the treatmentlocation, the catheter body having a lumen, an aspiration opening in asidewall thereof along the treatment length of the catheter body, and atleast one port along a proximal length of the catheter body; closingfluid communication between the port and the aspiration opening throughthe lumen; infusing a thrombolytic agent into the vessel through thelumen and at least one infusion opening located along the treatmentlength of the catheter body; activating an agitating mechanism locatedalong the treatment length of the catheter body to disrupt the clot;closing fluid communication between the port and the aspiration openingthrough the lumen; and aspirating dissolved clot, and any solid clotthat may be present, from the vessel through the aspiration opening andthe lumen. In a further aspect of the present embodiment, the agitatingmechanism comprises an elongate member having a non-linear portion alongthe treatment length of the catheter body. In a further aspect of thepresent embodiment, activating the agitating mechanism comprisesrotating and/or axially translating the agitating mechanism within theblood vessel and against the clot.

BRIEF DESCRIPTION OF THE DRAWINGS

The various embodiments of the present apparatus and methods for clotdisruption and evacuation now may be discussed in detail with anemphasis on highlighting the advantageous features. These embodimentsdepict the novel and non-obvious apparatus and methods shown in theaccompanying drawings, which are for illustrative purposes only. Thesedrawings include the following figures, in which like numerals indicatelike parts:

FIG. 1 is a top plan view of a catheter for use in an apparatus for clotdisruption and evacuation, and lytic distribution, according to one ofthe present embodiments;

FIG. 2 is a top plan view of an agitator for use in an apparatus forclot disruption and evacuation, and lytic distribution, according to oneof the present embodiments;

FIG. 2A is a detail view of the portion of FIG. 2 indicated by thecircle 2A-2A;

FIG. 3 is a cross-sectional view of the apparatus of FIG. 3 taken alongthe line 3-3;

FIG. 4 is a detail view of the portion of FIG. 1 indicated by the circle4-4;

FIGS. 5-8 are cross-sectional views of the apparatus of FIG. 4 takenalong the lines 5-5, 6-6, 7-7, 8-8, respectively;

FIG. 9 is a side cross-sectional detail view of a distal end of thecatheter of FIG. 1;

FIG. 10 is a detail view of the portion of FIG. 1 indicated by thecircle 10-10;

FIG. 11 is a cross-sectional view of the apparatus of FIG. 10 takenalong the line 11-11;

FIG. 12 is a cross-sectional view of the apparatus of FIG. 4 taken alongthe line 12-12;

FIG. 13 is a cross-sectional view of the apparatus of FIG. 10 takenalong the line 13-13;

FIG. 14 is a top plan view of the catheter of FIG. 1 coupled with theagitator of FIG. 2;

FIGS. 15 and 16 are side cross-sectional detail views of the portion ofFIG. 10 indicated by the circle 15/16-15/16;

FIG. 17 is a cross-sectional view of the apparatus of FIG. 4 taken alongthe line 17-17; and

FIGS. 13-25 are side elevation views of a method for clot disruption andevacuation according to one of the present embodiments.

DETAILED DESCRIPTION

The following detailed description describes the present embodimentswith reference to the drawings. In the drawings, reference numbers labelelements of the present embodiments. These reference numbers arereproduced below in connection with the discussion of the correspondingdrawing features.

The embodiments of the present apparatus and methods for clot disruptionand evacuation are described below with reference to the figures. Thesefigures, and their written descriptions, indicate that certaincomponents of the apparatus are formed integrally, and certain othercomponents are formed as separate pieces. Components shown and describedherein as being formed integrally may in alternative embodiments beformed as separate pieces. Components shown and described herein asbeing formed as separate pieces may in alternative embodiments be formedintegrally. Further, as used herein the term integral describes a singleunitary piece.

Directional terms used herein, such as proximal, distal, upper, lower,clockwise, counterclockwise, etc., are used with reference to theconfigurations shown in the figures. For example, a component that isdescribed as rotating clockwise when viewed from the perspectives shownin the figures may be described as rotating counterclockwise when viewedfrom the opposite perspective. Furthermore, the present embodiments maybe modified by altering or reversing the positions or directions ofmovement of various components. Accordingly, directional terms usedherein should not be interpreted as limiting.

FIGS. 1 and 2 illustrate one embodiment of apparatus for disrupting aclot in a blood vessel. With reference to FIG. 1, the apparatuscomprises a catheter body 50 having a proximal length 52 and a treatmentlength 54. A proximal balloon 56 and a distal balloon 58 are locatedalong the treatment length 54, and define proximal and distal ends,respectively, of the treatment length 54. The proximal length 52includes a plurality of ports, including a proximal balloon inflationport 60 and a distal balloon inflation port 62. With reference to FIG.3, the proximal balloon inflation port 60 is in fluid communication withan interior of the proximal balloon 56 through a proximal ballooninflation lumen 64 that extends through the catheter body 50 between theport 60 and the balloon 56. The distal balloon inflation port 62 is influid communication with an interior of the distal balloon 58 through adistal balloon inflation lumen 66 that extends through the catheter body50 between the port 62 and the balloon 58, and which is preferablyseparate from, and not in fluid communication with, the proximal ballooninflation lumen 64. With reference to FIG. 1, the proximal length 52further includes an infusion/aspiration port 63 that is in fluidcommunication with a plurality of infusion openings and an aspirationopening (shown in later figures) located along the treatment length 54through a combined infusion/aspiration lumen 70 (FIG. 3) that extendsthrough the catheter body 50 from the port 68 to the openings.

With continued reference to FIG. 1, each of the ports 60, 62, 68 caninclude an elongate tubular portion 72 that extends perpendicularly fromthe catheter body 50. In alternative embodiments, the tubular portions72 may extend from the catheter body 50 at a non-perpendicular angle.The balloon inflation ports 60, 62 are located adjacent one another on afirst side of the catheter body 50, and the infusion/aspiration port 68is located on a second, opposite, side of the catheter body 50 andproximally of the balloon, inflation ports 60, 62. However, theillustrated arrangement of the ports 60, 62, 68 is just one example, andother arrangements can be employed. At an end of each of the tubularportions 72 spaced from the catheter body 50, each port includes aconnector 74 configured to receive an infusion/aspiration device, suchas a syringe (not shown). For example, the connector 74 may comprise aLuer-type connector, such as a LUER-LOK® connector or a LUER-SLIP®connector.

The proximal length 52 of the catheter body 50 can further comprise asubstantially rigid tubular section 76 from which each of the ports 60,62, 68 extends. A proximal end of the rigid section includes a connector78 configured to receive an agitator 80, which is described below andillustrated in FIG. 2. For example, the connector 78 may comprise aLuer-type connector, such as a LUER-LOK® connector. The combinedinfusion/aspiration lumen 70 can extend through the proximal end of thetubular section 76, i.e. the proximal end includes an openingcorresponding to the location of the infusion/aspiration lumen 70.However, the balloon inflation lumens 64, 66 need not extend to theproximal end. Rather, these lumens can be closed at their respectiveproximal ends to facilitate maintaining pressure within the balloons 56,58 when they are inflated.

With continued reference to FIG. 1, and as described in further detailbelow, the catheter body 50 comprises a proximal section 82 and a distalsection 84. The proximal section 82 extends from the proximal end to alocation beneath the proximal balloon 56 (illustrated in further detailbelow). The distal section 84 is joined to a distal end of the proximalsection 82, and extends to a distal end of the catheter body 50, Asdetailed further below, the proximal and distal sections 82, 84 can havedifferent cross-sectional configurations, and may be formed of differentmaterials and/or may have different dimensions. In certain embodiments,for example, the proximal section 82 may have a greater stiffness thanthe distal section 84, such that the proximal section 82 is configuredfor pushability while the distal section 84 is adapted for navigatingtortuous vasculature.

The catheter body 50 is preferably sized and configured to be advancedthrough a patient's vasculature from a transcutaneous access site to atreatment site within the vasculature. Example dimensions for thecatheter body 50 include an outside diameter of approximately 8 French,or in the range of 4 French to 12 French, or outside diameters of0.095-0.097 inches and 0.085-0.087 inches for the proximal and distalsections, respectively; and a length in the range of 50 cm-200 cm, orabout 80 cm, or about 120 cm. Material(s) from which the catheter body50 is constructed is preferably rigid enough to allow the catheter 50 tobe pushed distally, but flexible enough to enable navigation of tortuousvasculature. Example materials for the proximal section 82 includepolyether block amide (PEBAX™), or any lubricious and/or hydrophilicpolymer such as nylon, polyethylene or EVA. One suitable compositioncomprises 39% Pebax 63D, 39% Pebax 72D, 20% BaSO4, and 2% TiO2. Similarmaterials may be used for the distal section 84; however, the materialof the distal section 84 can be softer than that of the proximal section82 so that it is more easily deflected by the agitator 80. One suitablecomposition comprises 78% Pebax 63D, 20% BaSO4, and 2% TiO2.

FIG. 3 illustrates the cross-sectional configuration of the catheter 50at the location of the line 3-3 in FIG. 4 (see area 4-4 in FIG. 1). Theinfusion/aspiration lumen 70 can have a circular cross-section, andoccupy a majority of the cross-sectional area of the catheter 50 (e.g.,60% or more, or two-thirds or more, or about 69% in the proximal section82 and/or 67% in the distal section 84). Each of the balloon lumens 64,66 can have a substantially kidney-shaped cross-section, and both lumens64, 66 can be located adjacent one another on a common side of theinfusion/aspiration lumen 70. A cross-sectional area of each of theballoon lumens 64, 66 can be substantially smaller than thecross-sectional area of the infusion/aspiration lumen 70. For example,the cross-sectional area of the balloon lumen(s) can be about 0.0003square inches in the proximal section 82 and about 0.0005 square inchesin the distal section 84, while the infusion/aspiration lumen can have across-sectional area of about 0.0034 square inches in the proximalsection 82 and about 0.0026 square inches in the distal section 84.

All three of the lumens 64, 66, 70 extend through the catheter 50 fromthe proximal length 52 to at least the location of the proximal balloon56. FIG. 4 is a detail view of the portion of the catheter 50 indicatedby the circle 4-4 in FIG. 1, which is within the region of the proximalballoon 56. The proximal and distal sections 32, 84 can be joined to oneanother at a joint 86 located beneath the proximal balloon 56. Forexample, the proximal and distal sections 82, 84 may be joined to oneanother with a butt joint 86, or any other suitable joint.

As discussed above, the proximal and distal sections 82, 84 of thecatheter body 50 may have different cross-sectional configurations.However, the infusion/aspiration lumen 70 extends through the entiretyof the catheter body 50, while the distal balloon inflation lumen 66extends through portions of both the proximal and distal sections 82,84, and the proximal balloon inflation lumen 64 extends through aportion of only the proximal section 82 (although arrangements otherthan the foregoing may be employed). Thus, the cross-sectionalconfiguration of the proximal section 82 of the catheter body 50 canchange toward the distal end thereof. With reference to FIG. 4, theproximal section 82 may be heated in a heating zone 83 that extends fromthe butt joint 86 to a location proximal of the proximal balloon 56. Theheating causes the material of the catheter body 50 to melt and reflow.An outer diameter of the catheter 50 reduces slightly, creating a neckedregion 90 at a proximal end of the heating zone 88. During the heatingprocess, mandrels (not shown) may be inserted through theinfusion/aspiration lumen 70, the proximal balloon inflation lumen 64,and the distal balloon inflation lumen 66, so that these lumens do notcompletely collapse.

FIG. 5 illustrates the cross-sectional configuration of an embodiment ofthe catheter 50 at the location of the cut line 5-5 in FIG. 4, which iswithin the heating zone 88 just distal of the necked region 90.Comparing FIGS. 3 and 5, the diameter of the infusion/aspiration lumen70 may be decreased in the heating zone 88. The sizes of the ballooninflation lumens 64, 66 may also be decreased, and their cross-sectionalshapes may be substantially oval as opposed to the kidney shape of FIG.3. This cross-sectional configuration of the catheter body 50 can extendtoward the distal end of the proximal section 82, until just proximal ofthe distal end. FIG. 6 illustrates the cross-sectional configuration ofthe catheter 50 at the location of the cut line 6-6 in FIG. 4, which isjust proximal of the distal end. The mandrel inserted into the proximalballoon inflation lumen 64 during heating may not extend through thedistal end of the catheter 50, such that the proximal balloon inflationlumen 64 completely collapses distally of the mandrel. Thisconfiguration seals the proximal balloon inflation lumen 64 so thatfluid injected into the proximal balloon inflation lumen 64 cannot flowpast the distal end of the proximal section 82 of the catheter 50, andis instead forced into the proximal balloon 56 through a proximalballoon inflation opening 92 (FIG. 7) in the side wall of the catheter50, as described further below. Instead of or in addition to the heatingprocedure described herein, other techniques (such as the use of a plugand/or adhesive) may be used to seal the distal end of the proximalballoon inflation lumen 64.

FIG. 7 illustrates an embodiment of the cross-sectional configuration ofthe catheter 50 at the location of the cut line 7-7 in FIG. 4, which isat the location of the proximal balloon inflation opening 92. Theproximal balloon inflation opening 92 provides a fluid path from theproximal balloon inflation lumen 64 to an interior space of the proximalballoon 56. The proximal balloon 56 can thus be inflated by infusingfluid, such as saline, into the proximal balloon 56 through the proximalballoon inflation lumen 64, through the proximal balloon inflationopening 92, and into the interior space of the proximal balloon 56. Theproximal balloon 56 can also be deflated by aspirating the fluid alongthe same path in the reverse order.

As discussed above, constructing the catheter body 50 from separateproximal and distal sections 82, 84 provides numerous advantages. Forexample, the proximal and distal sections 82, 84 may be constructed ofdifferent materials. A material of the proximal section 82 may havegreater rigidity compared to a material of the distal section 84. Such aconfiguration enables the catheter body 50 to be advanced through thebody by pushing from the proximal end, while maintaining flexibilityalong the treatment length 54 so that the treatment length 54 can moreeasily navigate tortuous vasculature and can accommodate an agitatorshaft 110 having a larger amplitude along the treatment length 112.Example materials for the proximal and distal sections 82, 84 arediscussed above.

Another advantage of constructing the catheter body 50 from separateproximal and distal sections 82, 84 is that these sections can moreeasily be made with differing cross-sections. For example, FIG. 8illustrates the cross-sectional configuration of the distal section 84of the catheter 50, at the location of the cut line 8-8 in FIG. 4, whichis just distal to the joint 86. The distal section 84 of the catheter 50can include the infusion/aspiration lumen 70 and the distal ballooninflation lumen 66, but not the proximal balloon inflation lumen 64. Thedistal section 84, lacking the proximal balloon inflation lumen 64 thatthe proximal section 82 includes, can thus be made separately from theproximal section 82, and the two sections can then be secured to oneanother at the joint 86. Both sections can be made using standardtechniques, such as extrusion, or any other processe(s). Alternatively,both sections can be made as a single piece or a single extrusion,without the joint 86.

With continued reference to FIG. 8, the combined infusion/aspirationlumen 70 and the distal balloon inflation lumen 66 continue through thedistal section 84 of the catheter 50 in the distal direction. FIG. 9illustrates a side cross-sectional view of an embodiment of the distalend of the catheter 50. The distal balloon inflation lumen 66 terminatesproximally of the distal end of the catheter 50. This configurationfacilitates maintaining pressure in the distal balloon 58 when it isinflated. The combined infusion/aspiration lumen 70 extends through thedistal end of the catheter 50 such that there is an opening 94 in thedistal end of the catheter 50 corresponding to the lumen 70. However, adistal end cap 96 can be employed to close the distal opening 94 of theinfusion/aspiration lumen 70. The distal end cap 96 is substantiallycylindrical with a tapered nose portion 98. The cap 96 fits over areduced diameter distal portion 100 of the catheter. A central portionof the cap 96 includes a narrow (relative to the infusion/aspirationlumen 70) opening 102 sized to allow a guide wire (not shown) to pass.The guide wire may be used when deploying the catheter 50 according tostandard techniques. Tire opening 102 also provides pressure relief inthe event that pressure within the infusion/aspiration lumen 70 rises.This pressure relief reduces the likelihood that fluids in the catheter50 will flow out the proximal end, a phenomenon known as “back bleed.”

FIG. 10 is a detail view of an embodiment of the portion of the catheter50 indicated by the circle 10-10 in FIG. 1, which is within the regionof the distal balloon 58 and the aspiration opening 104. The distalballoon 58 has been omitted from FIG. 10 for clarity. FIG. 11illustrates the cross-sectional configuration of the catheter 50 at thelocation of the cut line 11-11 in FIG. 10. At the location of FIG. 11, adistal balloon inflation opening 106 in the side wall of the catheter 50provides a fluid path from the distal balloon inflation lumen 66 to aninterior space of the distal balloon 58. The distal balloon 58 can thusbe inflated by infusing fluid, such as saline, into the distal balloon58 through the distal balloon inflation lumen 66, through the distalballoon inflation opening 106, and into the interior space of the distalballoon 58. The distal balloon 58 can also be deflated by aspirating thefluid along the same path in the reverse order.

Referring back to FIG. 4, FIG. 12 illustrates an embodiment of thecross-sectional configuration of the catheter 50 at the location of thecut line 12-12, which is located between the proximal and distalballoons 56, 58. In this region, referred to as the infusion/aspirationregion, the catheter 50 can include a plurality of infusion openings 108that extend from the infusion/aspiration lumen 70 radially outward andthrough the side wall of the catheter 50. In the illustrated embodiment,three infusion openings 108 are provided at the location of the cut line12-12. Additional such triads (or pairs, singles, etc.) of infusionopenings 108 can be provided at axially spaced locations along theinfusion/aspiration region. The axial spacing between triads may beuniform or variable.

At the location of each triad of infusion openings 108, the threeopenings 108 can be substantially uniformly spaced from one another atabout 120° apart in the circumferential direction. The illustratednumber and spacing of the infusion openings 108 is advantageous, as itprovides the capability to infuse a thrombolytic agent over a radialspan of substantially 360° around the outside of the catheter 50. Such“360° infusion” enables more uniform application of the thrombolyticagent to clot matter in the region of the treatment length 54 of thecatheter 50 to more efficiently break down the clot. 360° infusion isfacilitated at least in part by termination of the proximal ballooninflation lumen 64 proximally of the locations of the infusion openings103. Reducing the total number of lumens in the catheter 50 in theinfusion/aspiration region leaves a larger radial portion of thecatheter 50 through which the infusion openings 108 can extend from theinfusion/aspiration lumen 70 without interfering with other lumens.

As described in further detail below, thrombolytic agent may be infusedat a treatment site within a vessel by injecting the lytic at theinfusion/aspiration port 68 (FIG. 1), where it flows into and throughthe infusion/aspiration lumen 70 and eventually out the infusionopenings 108. Because the infusion openings 108 are distributed alongthe axial length of the catheter body 50, it is advantageous for adiameter of each infusion opening 108 to be small compared to a diameterof the infusion/aspiration lumen 70. Such a configuration facilitatesmaintaining a substantially uniform infusion pressure at each infusionopening 108, as opposed to more proximal infusion openings 108 havinghigher infusion pressures than more distal infusion openings 108. Forexample, in certain of the present embodiments a diameter of theinfusion/aspiration lumen 70 may be in the range 0.065-0.067 inches inthe proximal section 82 and 0.057-0.059 inches in the distal section 84,while a diameter of each infusion opening 108 may be in the range0.0025-0.0055 inches.

In certain embodiments, locations of at least some of the triads (orpairs, singles, groups of four, etc.) of infusion openings 108 may belocated at peaks 150 of the treatment length 112 of the agitator shaft110 (FIG. 2). Such a configuration locates the infusion openings 108 asclose as possible to the wall of the vessel at the treatment site formore effective chemical breakdown of the clot.

With reference to FIG. 10, the sidewall of the catheter body 50 canfurther include an aspiration opening 104 located in theinfusion/aspiration region. In the illustrated embodiment, theaspiration opening 104 is just proximal of the distal balloon 58. Thatis, the aspiration opening 104 is closer to the distal balloon 58 thanit is to the proximal balloon 56. This configuration providesadvantages. For example, during a treatment procedure where thetreatment site is accessed from an upstream location (antegrade), anoperator may deflate the proximal balloon 56 prior to aspiratingdissolved clot, and any solid clot that may be present, from thetreatment site. Blood will thus flow toward the treatment site and pushany fragmented matter toward the aspiration opening 104, making it morelikely that all of the fragmented matter will be aspirated out of thevasculature. Processes for using the present embodiments are describedin further detail below.

FIG. 13 illustrates the cross-sectional configuration of the catheter 50at the location of the cut line 13-13 in FIG. 10, which is located atthe aspiration opening 104. Note that the scale of FIG. 13 is largerthan that of the other cross-sectional views to more clearly illustratethe various layers of the apparatus. With reference to FIG. 13, theaspiration opening 104 provides fluid communication between theinfusion/aspiration lumen 70 and the vascular space surrounding thecatheter body 50. Further, a size of the aspiration opening 104 ispreferably adequate to allow the passage of dissolved clot, as well assolid pieces of clot that have been fragmented from the solid clotmatter in the vessel at the treatment site. These dislodged pieces canthus be drawn into the infusion/aspiration lumen 70 through theaspiration opening 104 and evacuated from the vessel, as described indetail below. For example, the aspiration opening 104 may have a lengthof about 0.22 inches and a width of about 0.08 inches, although othersizes or configurations may be employed.

Certain disclosed embodiments advantageously enable infusion ofthrombolytic agent and aspiration of dissolved clot, and any solid clotthat may be present, to be performed through the same lumen (theinfusion/aspiration lumen 70) in the catheter 50. Infusion andaspiration can be achieved with the aid of the agitator 80 (FIG. 2),which can be slidably received within the infusion/aspiration lumen 70,as described below. With reference to FIG. 2, the agitator 80 includesan elongate shaft 110 that is generally straight over its entire length,except along a treatment length 112 thereof, which includes a non-linearcurvature. (The agitator shaft 110 is shown in FIG. 2 as having a 180°bend merely for illustration purposes. In an at-rest state, the agitatorshaft 110 is generally straight except along the treatment length 112.)In the illustrated embodiment, the curvature of the treatment length 112is sinusoidal, but other forms of curvature could be provided instead.

The preferred agitator shaft 110 is generally flexible, but includessufficient rigidity that it may be pushed distally through theinfusion/aspiration lumen 70 by force applied at the proximal end of theagitator 80. Example materials for the agitator shaft 110 includemetals, such as stainless steel or any other metal displaying goodfatigue properties, and polymers, such as polytetrafluoroethylene(PTFE), polyether ether ketone (PEEK), or thermoplastic polyetherimide(ULTEM™), or any other stiff thermoplastic polymer with good fatigueproperties. The agitator shaft 110 is further sized to be slidablyreceived within the infusion/aspiration lumen 70. An outside diameter ofthe agitator shaft 110 may be in the range 0.0385-0.0425 inches, orabout 0.0410 inches. The agitator 80 may include a lubricious coating,such as a PTFE or FEP coating which may be applied via heat-shrink ordip coating.

In one embodiment, the shaft 110 includes a stainless steel core with anouter shell or coating of PTFE and PEEK. The PEEK is located along thetreatment length 112 only, while the PTFE covers substantially allportions of the shaft 110 and is positioned over the PEEK. ProvidingPEEK along the treatment length 112 facilitates forming the sinusoidalcurvature, because the PEEK can be heat set to permanently assume thecurved shape.

With reference to FIG. 2, the agitator shaft 110 extends distally froman oscillation drive unit (ODU) 114. The ODU 114 comprises a housing 116that can enclose a powered drive unit (not shown). The powered driveunit may comprise, for example, an electric motor, or any otherapparatus capable of rotating the agitator shaft 110. The powered driveunit may be connected to a power source (not shown), such as a battery,which may also be enclosed in the housing 116. An on/off switch 118 onthe housing 116 may be activated to start and stop rotation/oscillationof the agitator shaft 110. The on/off switch 118 may include anindicator light 120, such as a light-emitting diode (LED), that providesa visual indication when the powered drive unit is activated and theagitator shaft 110 is rotating/oscillating. Opposite sides of thehousing 116 may include raised ridges 122, or other tactile features, tofacilitate gripping of the ODU 114. Preferably, the ODU 114 is sized tobe comfortably gripped with one hand. A distal edge 124 of the housing116 includes a connector 126 that is configured to mate with theconnector 78 at the proximal end of the catheter 50 (FIG. 1). Forexample, the connector 126 may comprise a male Luer-type connector, suchas a LUER-LOK® connector, for sealing engagement with a female LUER-LOK®connector at the proximal end of the catheter 50.

In certain embodiments, a speed of rotation of the agitator shaft 110may be adjustable. Thus, with continued reference to FIG. 2, the ODU 114further includes a speed control 128. In the illustrated embodiment, thespeed control 128 is a rotatable knob, but in other embodiments couldcomprise other configurations, such as a sliding member. When theagitator shaft 110 is activated to rotate, adjustment of the speedcontrol 128 adjusts a speed of rotation of the agitator shaft 110. Thespeed of rotation of the agitator shaft 110 may be adjustable between,for example, 500 RPM (e.g. 400-600 RPM) and 3000 RPM (e.g. 2550-3450RPM).

Also in certain embodiments, an axial position of the agitator shaft 110relative to the ODU 114 may be adjustable. Thus, with continuedreference to FIG. 2, the ODU 114 further includes a translation bar 130.The translation bar 130 is operatively connected to the agitator shaft110, such that translating the translation bar 130 along the ODU 114moves the agitator shaft 110 away from and toward the ODU 114. Theoperator may move the translation bar 130 by, for example, cradling theODU 114 with one hand and sliding the translation bar 130 backward andforward with the thumb of the same hand. In certain embodiments, the ODU114 and the translation bar 130 may include detents (not shown) suchthat the agitator shaft 110 is translatable between or among discretepositions, such as three discrete positions, located along thelongitudinal range of motion of the agitator shaft 110. In otherembodiments, the agitator shaft 110 may be continuously translatable, inother words without discrete positions.

FIG. 2A illustrates a detail view of the distal end portion of anembodiment of the agitator shaft 110, as indicated by the circle 2A-2Ain FIG. 2. An outride diameter of the agitator shaft 110 can besubstantially constant over its length, except at the distal endportion, which can include an expanded diameter distill tip portion orvalve body 132. As described below, the distal tip portion 132 is sizedto substantially correspond to an internal diameter of theinfusion/aspiration lumen 70, with a slight clearance, so that theagitator 80 may be slid longitudinally within the infusion/aspirationlumen 70 without substantial difficulty.

FIG. 14 illustrates the agitator 80 engaged with the catheter body 50.The connectors 78, 126 on the catheter 50 and the ODU 114 are sealinglyengaged to secure the agitator 80 to the catheter body 50. The agitatorshaft 110 is received within the infusion/aspiration lumen 70, and thetreatment length 54 of the catheter 50 assumes the sinusoidal shape ofthe treatment length 112 of the agitator shaft 110. When the agitator 80is engaged with the catheter body 50, movement of the translation bar130 longitudinally translates the agitator shaft 110 within theinfusion/aspiration lumen 70, as described further below.

FIGS. 15 and 16 illustrate side cross-sectional views of the treatmentlength 54 of the catheter 50 in the region of the aspiration port, asindicated by the circle 15/36-15/16 in FIG. 10. With reference to FIG.15, the agitator shaft 110 is disposed within the infusion/aspirationlumen 70. The distal tip portion 132 substantially blocks fluid flowthrough the infusion/aspiration lumen 70. Depending upon whether thedistal tip portion 132 is positioned proximally or distally of theaspiration opening 104, either of infusion or aspiration may beperformed through the lumen 70, as described below. As discussed above,the agitator shaft 110 is linearly translatable within theinfusion/aspiration lumen 70 under the influence of the translation bar130. Thus, to switch between infusion and aspiration, the operator maytranslate the translation bar 130 proximally and distally to adjust therelative positions of the distal tip portion 132 and the aspirationopening 104, as described below.

For example, FIG. 16 illustrates the agitator shaft 110 with the distaltip portion 132 positioned proximally of the aspiration opening 104. Inthis position, fluid communication between the infusion/aspiration port68 (FIG. 1) and the aspiration opening 104 is substantially blocked.Thus, if fluid is infused through the infusion/aspiration port 68 itflows through the infusion/aspiration lumen 70 before being forced outof the infusion openings 108 (FIG. 12) proximal of the distal tipportion 132 (which itself is proximal of the aspiration opening 104),This position of the distal tip portion 132 may thus be referred to asthe infusion position, and may correspond to a second, or middleposition of the translation bar 130 with respect to the ODU 114.

By contrast, FIG. 15 illustrates the agitator shaft 110 with the distaltip portion 132 positioned distally of the aspiration opening 104. Inthis position, fluid communication between the infusion/aspiration port68 (FIG. 1) and the aspiration opening 104 is open. Thus, if suction isapplied at the infusion/aspiration port 68, it creates suction in theinfusion/aspiration lumen 70, which in turn creates suction at theaspiration opening 104. Disrupted pieces of clot and/or fluid can thusbe evacuated from the treatment site through the aspiration opening 104and the infusion/aspiration lumen 70. This position of the distal tipportion 132 may thus be referred to as the aspiration position. Further,because the interaction of the distal tip portion 132 and the aspirationopening 104 can switch the apparatus between an infusion state and anaspiration state, at least the distal tip portion 132 and the aspirationopening 104 may be referred to collectively as a valve, or aninfusion/aspiration valve. The aspiration position of the distal tipportion 132 may correspond to a third, or distal most position of thetranslation bar 130 with respect to the ODU 114.

With further reference to FIG. 15, and as discussed above, the agitatorshaft 110 in certain embodiments may include an inner core 134 and anouter sleeve 136. The inner core 134 and outer sleeve 136 may beconstructed of different materials. For example, the inner core 134 maybe constructed of a metal, such as stainless steel, and the outer sleeve136 may be constructed of a polymer, such as polytetrafluoroethylene(PTFE) and/or polyether ether ketone (PEEK).

With reference back to FIG. 4, the proximal balloon 56 can be locatedaround and secured to an outer surface of the catheter 50 at a proximalend of the treatment length 54 thereof. Similarly, with reference toFIG. 10, the distal balloon 58 can be located around and secured to anouter surface of the catheter 50 at a distal end of the treatment length54 thereof. The distal balloon 58 has been omitted from FIG. 10 forclarity. The balloons 56, 58 can be secured to the catheter 50 at eitherend, with an intermediate portion of each balloon 56, 58 being unsecuredto the catheter 50, so that upon inflation the balloons 56, 58 assume aspheroid shape or other similar shape suitable for occluding a vessel.The shape of the inflated balloons 56, 58 should not be interpreted aslimiting. Any expanded shape suitable for occluding a vessel, such as atorus or any other shape, is within the scope of the present disclosure.

The balloons 56, 55 may be constructed of one or more materials that arepreferably durable and elastic. For example, the balloons 56, 58 may beconstructed of a thermoplastic elastomer, such as ChronoPrene™, or othercompliant polymers such as ChronoFLEX™, Polyblend™, or Chronosil™.

In certain embodiments, the opposite ends of each balloon 56, 58 may bebonded to the catheter 50. For example, each balloon 56, 58 may be heatbonded to the catheter 50. However, in certain embodiments the balloons56, 58 may be constructed of ChronoPrene™, and the catheter distalsection 84 may be constructed of a polyether block amide. ChronoPreneand polyether block amide do not heat bond well to one another, and aresubject to delamination. The present embodiments solve thisincompatibility problem by introducing a tie layer 138 between eachballoon and the catheter 50.

FIG. 17 illustrates the cross-sectional configuration of one embodimentof the catheter 50 at the location of the cut line 17-17 in FIG. 4,which is located in the proximal bond region of the proximal balloon 56.With reference to FIG. 17, the tie layer 138 can be interposed betweeneach balloon 56, 58 and the catheter 50, and act as a link between thetwo. The tie layer 138 comprises a material that bonds well with boththe material of the balloons 56, 58 and the material of the catheter 50.In embodiments in which the balloons 56; 58 are ChronoPrene™ and thecatheter distal section 84 is a polyether block amide, the tie layer 138may comprise a compound of a polyoletin elastomer and polyether blockamide, or a compound of a polyolefin elastomer and urethane. In certainembodiments, the ratio of polyolefin elastomer to polyether block amideor urethane may be 60/40. Also in certain embodiments, the polyolefinelastomer may be the type sold under the trademark ENGAGE®, availablefrom Dow Chemical, and the polyether block amide may be the type soldunder the trademark PEBAX®, available from Arkema. In alternativeembodiments, the tie layer 138 may itself comprise more than one layer.For example, the tie layer 138 may comprise two layers, with an innerlayer of polyether block amide and an outer layer of polyolefinelastomer.

Where employed, the tie layer 138 provides advantages. For example, oneprior art method of securing balloons to catheters involves wrappingthread around the ends of each balloon. The thread increases the overalldiameter and stiffness of the device as compared to devices that don'tinclude thread. The tie layer 138 thus enables the insertion profile ofthe catheter 50 to be reduced, enabling it to be used in narrowerspaces. The tie layer 138 also provides greater directional specificity,reducing the likelihood of lopsided balloons adjacent to the pointswhere they are bonded to the catheter as compared to thread-wrappedballoons.

Method of Use

FIGS. 18-25 illustrate one embodiment of a method of use of the presentapparatus and methods for clot disruption and evacuation. The operatormay begin by preparing the apparatus, for example performing such stepsas flushing the infusion/aspiration lumen 70 with saline, filling twoballoon inflation syringes with saline and connecting them to theproximal and distal balloon inflation ports 60, 62, and/or filling asyringe with a thrombolytic solution and connecting it to theinfusion/aspiration port 68. Then, using standard techniques theoperator may gain vascular access at an access site (e.g. the poplitealvein behind the knee, the femoral vein at the groin, or in the brachialvein in the and) remote from a treatment site, and advance the catheter50 toward the treatment site (e.g., the inferior vena cava, or any ofthe following veins: isolated iliac, iliofemoral, isolated popliteal,isolated femoral, subclavian, or any other suitable vein or artery).

With reference to FIG. 18, the vessel 140 is occluded at the treatmentsite 142 by a clot 144 or thrombus. In various embodiments, the vessel140 may be completely occluded, or only partially occluded. As discussedfurther below, it is advantageous for the catheter 50 to be advancedtoward the treatment site 142 in the downstream direction, as indicatedby the arrows showing the direction of blood flow. However, the presentembodiments are not limited to this direction of approach.

With reference to FIG. 19, the catheter 50 is advanced through the clot144 until the distal balloon 58 is entirety distal of the clot 144.Advancement of the catheter 50 may be aided by a guide wire and/or anintroducer sheath using standard techniques. However, for clarity thosecomponents have been omitted from the figures. If a guide wire is used,the catheter 50 may be advanced over the guide wire with the guide wirepassing through the infusion/aspiration lumen 70 and the opening 102(FIG. 9).

With reference back to FIGS. 4 and 10, the catheter 50 may include oneor more marker bands 146 to aid in external visualization of theposition of the treatment length 54 of the catheter 50. In theillustrated embodiment, the catheter 50 includes a pair of radiopaquebands 146 positioned beneath each of the balloons 56, 58. Usingfluoroscopy, the operator may accurately position the treatment length54 of the catheter 50 at the treatment site 142 using the radiopaquebands 146 as a guide. Other external visualization techniques, such asultrasound, may be used instead of fluoroscopy, which is recited heremerely as one example technique.

With reference to FIG. 20, the distal balloon 58 is inflated bydepressing the plunger on the syringe connected to the distal ballooninflation port 62. The distal balloon 58 is inflated until it completelyoccludes the vessel 140 distal of the clot 144. Complete occlusion isadvantageous to prevent fragmented pieces of the clot 144 from flowingdownstream away from the treatment site 142.

With reference to FIG. 21, the agitator 80 is advanced through theinfusion/aspiration lumen 70 of the catheter 50 until the sinusoidallycurved treatment length 112 of the agitator 80 is positioned between theballoons. At this point, the operator connects the connectors on theproximal end of the catheter 50 and the distal edge of the ODU 114housing 116 to secure the agitator 80 to the catheter 50, The operatormay ensure that the translation bar 130 is in the first or secondposition, which correspond to infusion positions. Alternatively, theoperator may postpone this step until later in the procedure.

With reference to FIG. 22, the proximal balloon 56 is inflated bydepressing the plunger on the syringe connected to the proximal ballooninflation port 60. Again, the proximal balloon 56 is inflated until itcompletely occludes the vessel 140 proximal of the clot 144. At thispoint, the clot 144 is isolated between the inflated balloons.

With the translation bar 130 in the first or second position, theoperator next activates the ODU 114 to begin rotation/oscillation of theagitator 30. The operator may adjust the rotational speed of theagitator 80 using the speed control 128 (FIG. 2) until a desiredrotational speed is achieved. The treatment length 112 of the agitator80, with its sinusoidal curvature, acts to mechanically disrupt the clot144 along the treatment length and/or to disperse lytic at the treatmentsite to facilitate dissolving of the clot. The dimensions of thetreatment length 112 are such that it contacts the clot 144 when itrotates, disrupting and tearing away fragments thereof as it rotates.

While the agitator 80 rotates at the desired speed, the operator infusesa quantity of thrombolytic solution by depressing the plunger on thesyringe connected to the infusion/aspiration port 68. The lytic travelsthrough the infusion/aspiration lumen 70 and is distributed at thetreatment site 142 through the infusion openings 108 in the catheter 50(FIG. 12). The lytic acts to chemically break dawn the clot 144 so thatit may be more easily disrupted by the rotating agitator 80. Theoperator may periodically infuse additional discrete quantities ofthrombolytic solution as the procedure progresses. For example, theoperator may infuse additional lytic every thirty seconds, or everysixty seconds, or every ninety seconds, etc., until all of the lytic inthe infusion/aspiration syringe has been infused. The operator mayinfuse the same quantity of lytic each time, or may vary the infusedquantity from one infusion to another. For example, the operator mayinject a first quantity and a last quantity having the same volume, withone or more intermediate quantities having half of the volume of lyticas the first and last quantities. For example, during a ten minute runtime, the operator may follow an infusion schedule under which theoperator infuses 2 cc of lytic at the beginning of the run, and anadditional 1 cc of lytic at the end of each of the first through ninthminutes of the run.

Periodically while the agitator 80 is rotating the operator may adjustthe longitudinal position of the treatment length 112 of the agitator80. As described above, the translation bar 130 may include threediscrete positions. Two of these positions have been described abovewith respect to FIGS. 15 and 16. A third position, or proximal mostposition, may also correspond to an infusion position, in which theexpanded diameter distal tip portion or valve body 132 of the agitator80 is located proximally of the aspiration opening 104 in the sidewallof the catheter body 50. By alternating the agitator treatment length112 between the two infusion positions, the clot 144 can be moreeffectively disrupted, because the sinusoidal curvature of the treatmentlength 112 is brought to bear against a greater proportion of the lengthof the clot 144, and because the lytic is better dispersed. The operatormay, for example, adjust the position of the agitator 80 each time he orshe infuses lytic.

After the operator has infused the last quantity of lytic, the proceduremay continue with the agitator 80 rotating for a desired amount of time,such as 5-15 minutes. At this time, the operator may verify theeffectiveness of clot 144 disruption using any desired imagingtechnique, such as ultrasound, fluoroscopy, etc. If the results are notsatisfactory, the steps described above may be repeated. However, if theresults are satisfactory, the operator may begin aspirating dissolvedclot, and any fragmented pieces 146 of clot 144 that may be present,from the treatment site 142. FIG. 23 illustrates the treatment site 142after clot 144 disruption, with fragmented pieces 146 of the clot 144.The agitator 80 is not shown in FIG. 23 for clarity.

To aspirate, the operator may first reduce the rotational speed of theagitator 80. With reference to FIG. 24, the proximal balloon 56 may thenbe deflated if the procedure is being performed antegrade (i.e. bloodflow at the treatment site 142 is in the proximal-to-distal directionwith reference to the catheter 50). If the procedure is being performedretrograde, the distal balloon 58 is deflated while the proximal balloon56 remains inflated (not shown). The advantage of deflating the proximalballoon 56 for antegrade procedures and deflating the distal balloon 58for retrogrades is that blood flow entering the treatment area pushesthe disrupted clot 144 particles downstream where they are trapped bythe still inflated downstream balloon. When performed antegrade, thisdirection of flow has the additional advantage of pushing the fragmentedclot pieces 146 toward the aspiration opening 104 in the catheter 50,which is located closer to the distal balloon 58 than the proximalballoon 56.

The operator next moves the translation bar 130, and hence the agitator80, to the aspiration position in which the expanded diameter distal tipportion 132 of the agitator 80 is located distally of the aspirationopening 104 in the sidewall of the catheter body 50, as shown in FIG.15. The operator then aspirates the dissolved clot, and any fragmentedclot pieces 146 that may be present, from the treatment site 142 bydrawing back on the plunger of the infusion/aspiration syringe. Incertain embodiments, the operator may exchange an infusion syringe for aseparate and larger aspiration syringe prior to beginning aspiration.The dissolved clot, fragmented clot pieces 146, along with remnants ofany infused fluids and/or blood, are aspirated through the aspirationopening 104 (FIG. 25), and flow proximally through theinfusion/aspiration lumen 70 and into the infusion/aspiration syringe.The operator may need to perform this step more than once to ensure thatall fragmented clot pieces 146 are aspirated.

When aspiration is complete, the operator halts rotation of the agitator80, and removes the agitator 80 from the catheter 50. The operator maythen optionally reinsert a guide wire through the infusion/aspirationlumen 70. The operator then deflates the second balloon and withdrawsthe catheter 50.

The embodiments described herein may provide numerous advantages. Forexample, the catheter 50 can include only three lumens in its proximalsection 82, and/or only two lumens in its distal section 84. Reducingthe number of lumens enables the infusion/aspiration lumen 70 to be madelarger. A larger infusion/aspiration lumen 70 enables larger fragmentedclot pieces 146 to pass, malting it less likely that theinfusion/aspiration lumen 70 will get clogged. Reducing the number oflumens also enables “360° infusion,” which is discussed above.

One reason the present embodiments are capable of functioning with sofew lumens in the catheter 50 is because infusion and aspiration areperformed through the same lumen. There is thus no need for two separatelumens for infusion and aspiration. This functionality is at leastpartially enabled by the infusion/aspiration valve, which is discussedabove.

The above description presents the best mode contemplated for carryingout the present apparatus and methods for clot disruption andevacuation, and of the manner and process of making and using them, insuch full, clear, concise, and exact terms as to enable any personskilled in the art to which they pertain to make and use the presentembodiments. The present embodiments are, however, susceptible tomodifications and alternate constructions from that discussed above thatare fully equivalent. Consequently, the present apparatus and methodsare not limited to the particular embodiments disclosed. On thecontrary, the present embodiments cover all modifications and alternateconstructions coming within the spirit and scope of the presentembodiments as generally expressed by the following claims, whichparticularly point out and distinctly claim the subject matter of thepresent embodiments.

What is claimed is:
 1. Apparatus for disrupting a clot in a bloodvessel, the apparatus comprising: a catheter body having a proximallength and a treatment length, the treatment length being configured tobe disposed within a patient; at least one port along the proximallength of the catheter body; at least one infusion opening along thetreatment length of the catheter body; at least one aspiration openingalong the treatment length of the catheter body; a first lumen withinthe catheter body in fluid communication with the at least one infusionopening and in fluid communication with the at least one aspirationopening; a valve member configured to be disposed, in its entirety,within the treatment length of the catheter body, the valve beingconfigured to selectively open and close fluid communication between theat least one port and the at least one aspiration opening, wherein thevalve member comprises a body that is translatable longitudinally withinthe first lumen, and wherein the body of the valve member comprises afirst position located proximally of the at least one aspiration openingand a second position located distally of the at least one aspirationopening; and an agitator that is translatable longitudinally within thefirst lumen, wherein the agitator comprises the valve member.
 2. Theapparatus of claim 1, wherein when the body of the valve member is inthe first position the apparatus is configured to infuse a thrombolyticagent into the vessel through the first lumen and the at least oneinfusion opening, and when the body of the valve member is in the secondposition the apparatus is configured to aspirate a dissolved clot, andany pieces of solid clot that may be present, from the vessel throughthe at least one aspiration opening and the first lumen.
 3. Theapparatus of claim 1, further comprising an aspiration source; whereinwhen the body of the valve member is in the first position the bodysubstantially blocks fluid communication within the first lumen betweenthe at least one aspiration opening and the aspiration source, and whenthe body of the valve member is in the second position the body does notblock fluid communication within the first lumen between the at leastone aspiration opening and the aspiration source.
 4. The apparatus ofclaim 3, further comprising an infusion source; wherein when the body ofthe valve member is in the first position the body substantially blocksfluid communication within the first lumen between the at least oneaspiration opening and the infusion source, the body of the valve membertherefore being configured to cause fluid flowing from the infusionsource to flow out of the first lumen through the at least one infusionopening.
 5. The apparatus of claim 1, wherein the agitator comprises anelongate member having a non-linear portion along the treatment lengthof the catheter body.
 6. The apparatus of claim 1, wherein the body ofthe valve member is located on a distal portion of the agitator and istranslatable therewith along the first lumen.
 7. The apparatus of claim1, further comprising a first expandable member along the treatmentlength of the catheter body, the first expandable member defining afirst expandable internal volume.
 8. The apparatus of claim 7, furthercomprising a second lumen within the catheter body in fluidcommunication with the first expandable internal volume of the firstexpandable member.
 9. The apparatus of claim 8, further comprising asecond expandable member along the treatment length of the catheterbody, the second expandable member defining a second expandable internalvolume.
 10. The apparatus of claim 9, further comprising a third lumenwithin the catheter body in fluid communication with the secondexpandable internal volume of the second expandable member.
 11. Theapparatus of claim 10, wherein the second lumen terminates at the firstexpandable internal volume of the first expandable member and the thirdlumen terminates at the second expandable internal volume of the secondexpandable member.
 12. The apparatus of claim 9, wherein the at leastone infusion opening and the at least one aspiration opening are locatedbetween the first and second expandable members.
 13. The apparatus ofclaim 12, wherein the at least one infusion opening comprises aplurality of infusion openings that are spaced radially around thecatheter body, over a radial span of greater than 180° about thelongitudinal axis of the catheter body.
 14. The apparatus of claim 13,wherein the plurality of infusion openings are located on a portion ofthe catheter body that comprises no lumens other than the first lumenand the second lumen, the first lumen and the second lumen beingcollectively sufficient to facilitate infusion through the plurality ofinfusion openings, aspiration through the at least one aspirationopening, and expansion of one of the expandable members.
 15. Theapparatus of claim 7, wherein the catheter body comprises a proximalportion and a distal portion secured to one another at a joint, and thefirst expandable member surrounds the joint.
 16. The apparatus of claim15, wherein the joint is a butt joint.
 17. The apparatus of claim 1,wherein the at least one infusion opening comprises a plurality ofinfusion openings, and the plurality of infusion openings are spacedfrom one another both radially and longitudinally with respect to thetreatment length of the catheter body.
 18. The apparatus of claim 17,wherein the plurality of infusion openings are grouped in groups ofthree, with each group of three infusion openings being located at asame position along the treatment length of the catheter body.
 19. Theapparatus of claim 18, wherein the infusion openings in each group ofthree infusion openings are uniformly radially spaced 120° from oneanother.
 20. The apparatus of claim 1, wherein the agitator isconfigured to mechanically disrupt the clot and/or to disperse lytic tofacilitate dissolving the clot.